[Openstack-stable-maint] Stable check of openstack/tooz for ref refs/heads/stable/train failed

Build failed. - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/06950d01360b47cb926e4dfec6607b2d : SUCCESS in 5m 11s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/8cf1f4109e074843bed099d780991c0a : SUCCESS in 4m 09s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/0b41553f093b48e2a951a5df399bffab : FAILURE in 4m 29s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/22c697435f9a4cc0b3223893a4080a07 : SUCCESS in 5m 20s